package com.sky.service.impl;

import com.sky.context.BaseContext;
import com.sky.dto.ShoppingCartDTO;
import com.sky.entity.Dish;
import com.sky.entity.Setmeal;
import com.sky.entity.ShoppingCart;
import com.sky.exception.ShoppingCartBusinessException;
import com.sky.mapper.DishMapper;
import com.sky.mapper.SetmealMapper;
import com.sky.mapper.ShoppingCartMapper;
import com.sky.service.ShoppingCartService;
import org.springframework.beans.BeanUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.time.LocalDateTime;
import java.util.List;

@Service
public class ShoppingCartServiceImpl implements ShoppingCartService {

    @Autowired
    private ShoppingCartMapper shoppingCartMapper;
    @Autowired
    private DishMapper dishMapper;
    @Autowired
    private SetmealMapper setmealMapper;
    /**
     * 添加购物车
     * @param shoppingCartDTO
     */
    @Override
    public void addCart(ShoppingCartDTO shoppingCartDTO) {
        //判断当前加入到购物车中的菜品或套餐是否在购物车中
        ShoppingCart shoppingCart = new ShoppingCart();
        BeanUtils.copyProperties(shoppingCartDTO,shoppingCart);
        Long userId = BaseContext.getCurrentId();
        shoppingCart.setUserId(userId);
        List<ShoppingCart> list = shoppingCartMapper.list(shoppingCart);
        //如果存在，则增加数量+1
        if (list != null && !list.isEmpty()) {
            ShoppingCart cart = list.get(0);
            cart.setNumber(cart.getNumber() + 1);
            shoppingCartMapper.updateNumberById(cart);
        }else {
            //不存在插入一条数据
            Long dishId = shoppingCartDTO.getDishId();
            if(dishId != null){
                //添加菜品
                Dish dish = dishMapper.selectById(dishId);
                shoppingCart.setName(dish.getName());
                shoppingCart.setImage(dish.getImage());
                shoppingCart.setAmount(dish.getPrice());

            }else {
                //添加套餐
                Long setmealId = shoppingCartDTO.getSetmealId();
                Setmeal setmeal = setmealMapper.getById(setmealId);
                shoppingCart.setName(setmeal.getName());
                shoppingCart.setImage(setmeal.getImage());
                shoppingCart.setAmount(setmeal.getPrice());
            }
            shoppingCart.setNumber(1);
            shoppingCart.setCreateTime(LocalDateTime.now());
            shoppingCartMapper.insert(shoppingCart);
        }
        //否则添加到购物车
    }

    /**
     * 查看购物车
     * @return
     */
    @Override
    public List<ShoppingCart> showShoppingCart() {
        //设置用户id
        Long userId = BaseContext.getCurrentId();
        ShoppingCart shoppingCart = ShoppingCart.builder()
                .userId(userId)
                .build();
        List<ShoppingCart> list = shoppingCartMapper.list(shoppingCart);
        return list;
    }

    /**
     * 清空购物车
     */
    @Override
    public void cleanCart() {
        Long userId = BaseContext.getCurrentId();
        shoppingCartMapper.deleteByUserId(userId);
    }

    /**
     * 删减购物车
     * @param shoppingCartDTO
     */
    @Override
    public void subCart(ShoppingCartDTO shoppingCartDTO) {
        ShoppingCart shoppingCart = new ShoppingCart();
        BeanUtils.copyProperties(shoppingCartDTO, shoppingCart);

        Long userId = BaseContext.getCurrentId(); // 获取当前用户ID
        shoppingCart.setUserId(userId); // 设置用户ID，避免漏传

        List<ShoppingCart> list = shoppingCartMapper.list(shoppingCart); // 根据 dishId/setmealId + userId 查询

        if (list != null || !list.isEmpty()){
            ShoppingCart cart = list.get(0); // 取出第一条记录

            if (cart.getNumber() > 1) {
                cart.setNumber(cart.getNumber() - 1);
                shoppingCartMapper.updateNumberById(cart);
            } else {
                shoppingCartMapper.removeCart(cart); // 删除该条购物车记录
            }
        }else {
            throw new ShoppingCartBusinessException("购物车为空");
        }

    }
}
